自动化配置ssh连接

自动化配置ssh连接

在从主机使用ssh连接其他的主机时往往要求一些不同的响应信息。

例如第一次访问时:

#ssh root@localhost
The authenticity of host 'localhost (::1)' can't be established.
ECDSA key fingerprint is 03:cc:13:fe:6c:85:0a:af:df:67:de:18:19:ae:d8:1f.
Are you sure you want to continue connecting (yes/no)?

在你输入yes下一步你将发现下如下的输出：

root@localhost's password: 

此时要求你输入root的密码。在你输入正确的密码后，你就可以看到如下输出：

Last login: Tue Jun 14 20:45:07 2016 from 192.168.12.1
[root@LINUXTEST ~]# 

我们如果希望实现ssh的自动化操作，并且在远程主机上执行某一个操作，例如：

root@LINUXTEST .ssh]# ssh root@localhost hostname 
The authenticity of host 'localhost (::1)' can't be established.
ECDSA key fingerprint is 03:cc:13:fe:6c:85:0a:af:df:67:de:18:19:ae:d8:1f.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
root@localhost's password: 
LINUXTEST

在这个过程中，你需要输入yes,password这两个值。

在这里只靠shell自身是无法完成，需要一个expect的工具来帮助我们。

• 安装expect

  #yum install expect -y
  
  Installed:
      expect.x86_64 0:5.45-14.el7_1
  
  Dependency Installed:
      tcl.x86_64 1:8.5.13-8.el7
  
  Complete!
  

• 创建如下脚本autossh.sh

  # vi autossh.sh
      #!/usr/bin/expect
      set ipaddr "localhost"
      set password "root1234"
  
      spawn ssh root@$ipaddr
      expect {
      "yes/no" { send "yes\r";exp_continue }
      "password:" { send "\r" }
      }
      expect "]#"
      send "pwd;hostname \r"
      expect eof
      exit
  # chmod u+x autossh.sh 
  

• 执行这个脚本，得到如下输出

  # ./autossh.sh 
  spawn ssh root@localhost
  The authenticity of host 'localhost (::1)' can't be established.
  ECDSA key fingerprint is 03:cc:13:fe:6c:85:0a:af:df:67:de:18:19:ae:d8:1f.
  Are you sure you want to continue connecting (yes/no)? yes
  Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
  root@localhost's password: 
  Last login: Tue Jun 14 20:56:38 2016 from 192.168.12.1
  [root@LINUXTEST ~]# pwd;hostname 
  /root
  LINUXTEST
  

• 接下来我们只需要创建一个包含所有主机的用户名与密码的文件h-u-p.txt，里面包含如下的内容

  #vi h-u-p.txt
  hostname1:username1:password1
  hostname2:username2:password2
  hostname4:username3:password3
  hostname4:username4:password4
  .......
  

• 编写另外一个脚本batchssh.sh来处理这些参数并且调用autossh.sh

  #vi batchssh.sh
      #!/usr/bin/bash
  
      for line in $(cat h-u-p.txt)
              do
              arr=(${line//:/ })
              ./autossh.sh ${arr[0]} ${arr[1]} ${arr[2]}
      done
  

• 修改autossh.sh为

      #>autossh.sh
      #vi autossh.sh
          #!/usr/bin/expect
          set ipaddr [lindex $argv 0]
          set username [lindex $argv 1]
          set password [lindex $argv 2]
  
          spawn ssh $username@$ipaddr
          expect {
          "yes/no" { send "yes\r";exp_continue }
          "password:" { send "$password\r" }
          }
          expect "]#"
          send "pwd;hostname;exit \r"
          expect eof
          exit
  

• 那么现在就可以编辑文件h-u-p.txt来批量执行ssh连接了。文件列表如下：

  autossh.sh  batchssh.sh  h-u-p.txt